The present invention relates to an image reading device, a copy apparatus and an image reading method.
A conventional image reading device includes a reading means for reading a manuscript along a main-scanning direction as well as reading image information of the manuscript which relatively moves along a sub-scanning direction, and a determination means for determining whether there is a specific image in the image information or not (for example, an image reading device disclosed in JP-A-2002-77609).
In the image reading device disclosed in JP-A-2002-77609, the determination means discriminates a specific image based on arrangement relation of marks. The means extracts marks included in image information, calculates distances between marks and determines that there is the specific image in the image information when the distances between marks correspond to distances in the specific image.
The conventional image reading device having such configuration is mounted on, or connected to a copy apparatus and the like having a printing means for performing printing based on image information. The image reading device is capable of, when determining that there is a specific image in image information, taking illegal copy prevention measures such as stopping image reading and the like. Accordingly, the image reading device discriminates a specific image included in a manuscript such as a banknote or a classified document and restricts reading of inappropriate reading of the image to prevent illegal copying.
In order to prevent the image reading device from being misused as illegal copies of a banknote or a classified document, it is preferable to improve determination accuracy of a determination means for determining whether image reading is inappropriate or not.
However, processing of discriminating the specific image included in a banknote or a classified document will be processing imposing large burden with the improve of the determination accuracy, therefore, there is a case that a long period of time is necessary for the determination processing. In this case, since it takes a long time to be determined by the determination means, there arises a problem that waiting time for a user will be long.